Ricky Hatton has confirmed that he will give up his IBF light welterweight title in order to step up a division to fight American Luis Collazo on 13 May.
Hatton won the WBA light-welterweight belt last year
Hatton has rejected a fight with the IBF's mandatory challenger Naoufel Ben Rabah in favour of a crack at the WBA welterweight title.
The 27-year-old had won the IBF belt by beating Kostya Tszyu last summer.
"Winning the IBF title was the greatest night of my life. To give it up outside the ring is truly painful," he said.
"It has never been my or my team's intention not to defend my title against the IBF's appointed challenger but sadly due to outside influences, legal problems and problems meeting TV schedules, this is the situation I find myself in."
Hatton had said earlier this week that he hoped that by beating Collazo in Boston in May it would open the door to even bigger fights at 147lb.
"After that fight there should be a few more big-name bouts for me," he told The Sun.
"They would be career-defining fights for me - and with all due respect to Rabah he cannot be counted among the big names.
"In an ideal world I'd like to keep all belts but that is not possible in this day and age."
Rabah, an Australian-based Tunisian, won an IBF eliminator last September against Mexico's Arturo Morua but will now face another opponent for the vacant title.